On Tue 06 Feb 2018 at 20:23:13 -0500, Michael Stone wrote: > On Wed, Feb 07, 2018 at 01:16:28AM +0000, Brian wrote: > > On Tue 06 Feb 2018 at 19:53:16 -0500, Michael Stone wrote: > > > > > On Tue, Feb 06, 2018 at 11:00:12PM +0000, Brian wrote: > > > > On Tue 06 Feb 2018 at 17:06:36 -0500, Gene Heskett wrote: > > > > > On Tuesday 06 February 2018 14:07:55 Brian wrote: > > > > > > > > > > > > 1. auto enp0s25 > > > > > > iface enp0s25 inet > > > > > > static address 192.168.0.202 > > > > > > netmask 255.255.255.0 > > > > > > gateway 192.168.0.1 > > > > > > network 192.168.0.0 > > > > > > > > > > > > netmask and network are not needed. ifupdown will compute them. Note > > > > > > there are no examples in interfaces(5) which use these parameters. > > > > > > > > > > > You should go and read that man page again. > > > > > > > > I didn't have to but I did. A line beginning "netmask" is not required". > > > > > > If you don't specify a netmask it will default to something that was > > > correct > > > in the 80s and is probably wrong on your network. The "netmask line" isn't > > > required, but if you don't have a netmask line you should specify the > > > netmask in the address line (using "ip/netmask" syntax). > > > > Indeed. But a netmask line (while not necessary) doesn't do any harm. > > More than that: either a separate netmask entry or a netmask specified as > part of the address are almost certainly required for proper operation. It's > not technically required, but it is practically required.
The changelog says: * Calculate netmask internally, so even if a user haven't supplied one or have used CIDR notation, hook scripts will have it properly specified in IF_NETMASK environment variable. What is the significance of "...so even if a user haven't supplied ..."? -- Brian.